Barber Giant Mealybug | Puto barberi (Cockerell)

California Pest Rating for

Barber Giant Mealybug | Puto barberi (Cockerell)

Hemiptera: Putoidae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

Puto barberi is currently Q-rated. A permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background:Puto barberi is a common neotropical mealybug. Immatures and adult females are covered in a powdery, white wax. Adult females reach 4.3 mm in length. This polyphagous mealybug has been reported to feed on 37 families of plants, including Apocynaceae, Asteraceae, Bromeliaceae, Caprifoliaceae, Caryophyllaceae, Euphorbiaceae, Fabaceae, Geraniaceae, Lamiaceae, Lauraceae, Lomariopsidaceae, Lythraceae, Malvaceae, Nyctaginaceae, Oleaceae, Polygonaceae, Rosaceae, Rubiaceae, Rutaceae, Solanaceae, Sterculiaceae, Tamaricaceae, Thunbergiaceae, Umbelliferae, and Verbenaceae (Malumphy, 2014; Portilla and Cardona, 2004). It can be found on the foliage, fruit, and roots of plants (García Morales et al., 2016). It is a well-known pest of coffee; it feeds underground on the roots of that plant and has been reported to be the most significant mealybug pest of coffee in Colombia (Villegas-García and Benavides-Machado, 2011). The underground lifestyle makes insecticidal control challenging (Builes et al., 2014). It has also been reported from avocado, citrus, and strawberries, but no information was found regarding the damage inflicted (if any) (García et al., 2013; Kondo and Muñoz, 2016; Williams and Granara de Willink, 1992). Besides removing the phloem when feeding, an additional impact on plants that has been reported is the excretion of honeydew and resulting growth of mold on the plant. In addition to impacting the appearance of the plant, mold can reduce photosynthesis (Malumphy, 2010). Puto barberi has been shown to be parthenogenetic under laboratory conditions. It is not known if sexual reproduction occurs in the field (García et al., 2013).

Worldwide Distribution:Puto barberi appears to be restricted in distribution to the Neotropics, where it is apparently native, and the Canary Islands, where it is presumably introduced (Gavrilov-Zimin and Danzig, 2015; Malumphy, 2014). It is widespread in the Caribbean, including Antigua and Barbuda, Bahamas, Dominican Republic, Jamaica, Puerto Rico, and Trinidad and Tobago (Portilla and Cardona, 2004; Miller, 2005; Williams and Granara de Willink, 1992). It is also reported from South America (Colombia and Venezuela) (Kondo et al., 2008; Urtiaga, 2017).

Official Control:Puto barberi is considered reportable by USDA-APHIS (USDA-APHIS).

California Distribution: Puto barberi is not known to be present in California (Symbiota Collections of Arthropods Network).

California Interceptions:Puto barberi was intercepted on cut flowers of Alpinia sp. from Florida in 2018 (California Department of Food and Agriculture).

The risk Puto barberi would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction:Puto barberi is reported to attack a wide variety of plants, and it is likely that it could find suitable host plants in much of California. Climate, however, is expected to limit the potential distribution of this species in California. This mealybug appears to currently be limited to areas with a tropical or (possibly) subtropical climate; this includes the areas it has been introduced to in the Canary Islands. It does not appear to have spread into the southeastern United States or Mexico or further south than Colombia or Venezuela in South America, which supports the idea that a tropical/subtropical climate is required by this species. If this mealybug was able to become established in California, it would likely be limited to a very small area, possibly on the coast in the southern part of the state. Therefore, Puto barberi receives a Low (1)in this category.

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.

– Medium (2) may be able to establish in a larger but limited part of California.

– High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: As stated above, Puto barberi is reported to feed on at least 37 families of plants. Therefore, it receives a High (3) in this category.

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

3) Pest Reproductive and Dispersal Potential:Puto barberi has been shown to be parthenogenetic, which means a single female can establish a population. Immatures and adult females could be transported on infested plant material. Therefore, it receives a High (3)in this category.

– Low (1) does not have high reproductive or dispersal potential.

– Medium (2) has either high reproductive or dispersal potential.

– High (3) has both high reproduction and dispersal potential.

4) Economic Impact: Coffee is now being grown in several California counties, including San Diego and Santa Barbara (Kan-Rice, 2017). Puto barberi is considered a significant pest of coffee. It is possible that if this mealybug became established in southern California, it could have an impact on coffee, including lowering yield and increasing production costs. As a highly polyphagous mealybug, it could attack other crops as well. The presence of this pest in California could result in quarantines because it is considered Reportable by the USDA. Therefore, it receives a High (3)in this category.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 3

– Low (1) causes 0 or 1 of these impacts.

– Medium (2) causes 2 of these impacts.

– High (3) causes 3 or more of these impacts.

5) Environmental Impact:Puto barberi is reported to attack a wide variety of plants. If this species became established in California, it could trigger treatments in cropland or gardens. Therefore, it receives a Medium (2)in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

Environmental Impact: D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

Consequences of Introduction to California for Puto barberi: Medium (12)

Add up the total score and include it here.

–Low = 5-8 points

–Medium = 9-12 points

–High = 13-15 points

6) Post Entry Distribution and Survey Information:Puto barberi is not known to occur in California. It receives a Not established (0) in this category.

–Not established (0) Pest never detected in California, or known only from incursions.

–Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

–Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

–High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (12)

Uncertainty:

The most significant uncertainty involved with this proposal is the climatic suitability of California for Puto barberi. The known distribution of this species strongly suggests that it might not be capable of becoming established in climates other than tropical/subtropical. Even if this mealybug is able to become established in California, there is uncertainty regarding its ability to impact crops in California. Information was not found regarding impacts of this species on any crops other than coffee.

Conclusion and Rating Justification:

Puto barberi is a polyphagous mealybug that is a recognized pest. If it was able to become established in California, it could attack a variety of crops and ornamental plants. It is not known to be present in California. For these reasons, an “A” rating is justified.